Wireless interfering?

I have a question as to whether having a wireless network set up would interfere with other people's internet access.
The girls on my floor in my soroity house told us we were not allowed to set up a wireless network becuase it would interefere with the rest of the house's internet access and was the reason some of the girl's internet wasn't working.
I don't see though how have wireless set up for my floor would be any different than have 25 girls connected through the ethernet cables.
I can understand not wanting us to have an unsecure network where anyone near the house could use it, however would it really interfere with the rest of the house getting internet?

Probably someone tried to set one up in the past and the hardware caused a conflict to the rest of the wired network and they blamed it on being wireless since it was a new fad.

Then again, this is just a guesstimate: without any detail, it is difficult to comment on particular incident. There is a lot of misunderstanding about wireless networking out there - many made up their mind against it before they even had a chance to try. One of the managers at my new office is such an example - he will probably never know what he is missing!